Fig. 6.

Naloxone protects CA1 neurons from postischemic neurodegeneration. (a–l) Representative toluidine blue-stained coronal brain sections at the level of the dorsal hippocampus from control and experimental animals subjected to saline (a and b), naloxone (1 mg/kg; c and d), ischemia and saline (e and f), ischemia and naloxone (0.1 mg/kg or 1 mg/kg, 1 h before ischemia; g–j), or ischemia and naloxone [1 mg/kg twice (1 h before and 1 h after ischemia); k and l). Animals were killed 7 days after reperfusion. (m) Summary data for a–l. Ischemia elicited selective, delayed death of CA1 pyramidal neurons. Naloxone at doses and times examined significantly protected CA1 neurons. ∗, P < 0.05; ∗∗, P < 0.01. Low- and high-magnification panel widths are 2.5 and 0.25 mm, respectively.